New research suggests that the answer to this question is YES. As you might have noticed, a lot of information regarding the impact of environment on genes has been published recently. Take cancer, for example. One may be genetically predisposed to a certain cancer that runs in one’s family. However, simply possessing this gene does not determine one’s health outcomes or health destiny. It has become clear that in many cases, we can profoundly compensate for the genetic hand that we been dealt by controlling our environment. Smoking is a clear example: it is common knowledge that abstaining from cigarette smoking dramatically reduces one’s risk for lung cancer. This is a widely understood and powerful example of epigenetics, a concept referring to the idea that environment influences genetic expression. This represents a departure from the traditional view of genetics. Scientists now know that it’s not simply a matter of whether one carries a gene for a disease (cancer, heart disease, dementia, etc), but whether one expresses that gene. And whether we express that gene has much to do with our lifestyle choices (environment) – these lifestyle factors may influence genes in a way that disease does not manifest. Another way of saying this is that we are not entirely at the mercy of our genes.
So, what does this have to do with overweight? A recent study demonstrated that high BMI (body mass index) due to excess fat can modify a person’s DNA in several places on the DNA strand. These changes resulted from an alteration in methylation patterns (methylation is a process where methyl groups are added at specific sites in DNA molecules and is influenced by the cellular environment). Inflammation and micronutrient availability within cells are examples of these alterations that affect methylation patterns. This study confirms that cellular environment – specifically, excess fat tissue – affects genetic expression. Carrying excess weight can therefore impact genetic expression.
For more details, download the abstract entitled, Epigenome-wide association study of body mass index, and the adverse outcomes of adiposity, published in the January 2017 issue of Nature. (Abstract 2581)